TWI264841B - Light-emitting device and its manufacturing method - Google Patents

Abstract

The present invention is related to a kind of light-emitting device having the organic layer and its manufacturing method. The light-emitting device is provided with several coating layers between a base contact and a top contact. The purpose of the invention is to raise the capability of making structure of the coating layer by improving the coating layer structure. In the invention, the purpose stated above is obtained by the arrangement of the coating layer structure; and the specific method is to arrange at least one polymer coating layer and two molecular coating layers such that two conditions are considered in the following. When the top contact is a cathode, the coating layer adjacent to the top contact is designed as an electron-transporting molecular layer and is doped with an organic or inorganic donor; and the electron-transporting layer contains a principal organic substance and a donor-type doping substance with the molecular weight of the dopant larger than 200 g/mole. When the top contact is an anode, the layer adjacent to the top contact is designed as a p-type doped hole-transporting molecular layer and is doped with an organic or inorganic acceptor; and the hole-transporting layer contains a principal organic substance and an acceptor-like doping substance with the molecular weight of the dopant larger than 200 g/mole. For the method proposed in the invention, at least a coating method is used to dispose a polymer coating layer and at least a vapor deposition method is used to dispose one molecular layer. In addition, doping of the molecular coating layer is conducted by mixing the vapor deposition from two separately controlled doping sources in vacuum ambient.

Description

1264841 IX. Description of the invention: Molecular coating formed The present invention is a light-emitting element having an organic coating, particularly a light-emitting diode. The optical component of the present invention is composed of a plurality of coatings on the substrate between the bottoms and the two top contacts, the coatings comprising = δ composition (tetra) coating, and by vacuum The present invention also includes a method for manufacturing such a light-emitting element. This method firstly sets a bottom contact on the substrate, and the button is further coated thereon. Set a top contact. Since Tang et al. [CW Tang et al, Appl ~ (10) 913 (1987)] proposed a low-voltage organic light-emitting diode in 1987, the light-emitting diode is Wei-species. It can be used to manufacture large-scale ageing devices and components that have great potential in many other applications, such as the manufacture of lighting components. Light-emitting diodes are made of - very thin (typical thickness of seven (8) organic materials ^ coating Lai Cheng, and these organic materials are preferably in a vacuum, the molecular type is treated (that is, forming a so-called QLED), coated from a solution towel by centrifugation, printed, or In other appropriate ways, the money is gone (polymer, that is, the so-called PLE) D). As long as the applied voltage is applied to the carrier from the ageing person (the side is the electron H is a hole), the organic coating between the contacts can be formed via the exciton formed in the master wipe. (Electron_hole pairs) and the luminosity of these excitons are combined to generate light, and these light rays are emitted from the light emitting diode. The PLED type organic light emitting diode generally has the following coating structure: Transparent substrate, such as glass) 1264841 2 · Anode (transparent anode, usually indium tin oxide (IT〇)) 3. Hole transport layer or hole injection layer (usually pED〇T: pss or contains miscellaneous (eg PSS) PANI-POLYANILIN; PEDOT = Polyethyienedioxythiophene (polyethylenedioxythiophene), pss = Polystyrenesulfonate (polystyrene sulfonate) 4. Active polymer (light emission) 5. Cathode (usually Metals with less work (such as Mamba or Ma) as cathode coatings (that is, hole transport layers or hole injection layers) and active polymers are all from the observational filaments (dissolved core other solvents) Made by shouting solution. The contacts (anode and cathode) are usually made of vacuum. In the case of a display, the application of the above coating structure has the advantage that a variety of processes can be used to make the polymer coating, and some processes of the towel can produce a simple PLED lateral structure, which is also called Ink_Jet printing. Inkjet printing is to print different polymers as the three primary colors in a predetermined position, so that different kinds of radiation colors can be formed in the adjacent regions. The disadvantage is that if the number of different polymer coatings exceeds two, it becomes meaningless because the substrate material cannot be affected by the solute, so it is necessary to select a solvent which does not affect each other as a solvent of the polymer. This means that in addition to luminescence, the luminescent polymer must also be suitable for electron transport and electron injection from the cathode, and this requirement imposes significant limitations on the material selection and structural optimization of the polymer. Another disadvantage is that the order of the given material systems is difficult to change, for example in the above examples it is necessary to start from the anode. This shortcoming is for 1264841 k. PLEDs which are placed on the active substrate display substrate Display Substrate) and have 11-channel transistors as circuit elements are particularly noticeable. In addition, the use of transparent top contacts (as cathodes) is often a difficult task, as transparent top P contacts (such as IT〇) are typically fabricated using an off-premise process. However, the killing process will destroy the ingredients. Since the uppermost layer of the PLED is a luminescent coating layer, the luminous efficiency of the organic light emitting diode is lowered. In order to improve the resistance to the reduction of the skin, an additional layer of a small molecule coating can be applied by steaming in a vacuum. Doing so alone from the cathode can still cause problems. Another disadvantage of the upper 4 coating structure is that only a very unstable contact material (such as 1 bar or mother) can be used to achieve a sufficiently efficient electron injection. However, these unstable joint materials (e.g., about or about) have a lack of Ek that is easy to interact with oxygen or water.丄 OLED type organic light-emitting diodes are composed of small molecules that are vacuum-tested. As long as the small molecules constituting the coating of the OLED are slightly smaller, most of the fractions can be coated without any damage through heat treatment. Since the free path is long, the molecules are coated by vacuum distillation. j = the injection of the organic layer into the organic coating, as well as the improvement of transport transport, %, organic or inorganic dopants can be used as acceptors (for hole doping) and / or "(four) sub_ ) by the combination of the field = miscellaneous. At the beginning of the mixed steaming, until the fronting of the used material is plated (also added, for example, before (4), the dopant must not appear in its final form. _ Usually (4) mixing (5) fiber plating (four) wire reaching According to Decai Q 58 578 (M. pfdffo poor * " with organic 1246841 inner layer of light-emitting elements"), in addition to the doping wheel has a specific kinetic energy characteristics of the inherent Μ # f, to add The upper layer has a middle layer (that is, an undoped intermediate so the structure of the OLED is - a heterostructure: 1 · carrier, substrate; [empty: f into the electrode (anode = positive), Moreover, it is preferably a transparent electrode; 3. P-doped hole, injection and transport layer; the object 10 can be matched with the coating surrounding the coating; 5. luminescent coating; The interlocking layer (the thickness is usually smaller than the coating mentioned below), the coating of the electronic end layer (4) is required to be (4) matched with the coating of the ring; layer 7 · n-type doping electron, injection and transport layer; 8. Electron injection electrode, which is a kind of metal with low work function (cathode = negative) The advantages of the above coating structure include that each coating can be separately optimized, the distance between the luminescent coating and the joint can be adjusted to a large extent, and the carrier flow is injected into the organic coating very well, and The poorly conductive coating (4, 5, 6) has a small thickness.

Blochwitz, Sh. Liu, Κ· Leo, Appl· Phys· Lett·, 80, 139-141 (2002)

The working voltage described in the article "Low-electrolytic organic electroluminescent element using a pin structure" is extremely small (optical density: 100 cd/m2, operating voltage is less than 2.6 V), but the luminous efficiency is very low. In addition, the German patents DE 101 35 513.0 and X.Q 1264841

Zha〇et a1·, Αρρ1· Lett. 81,922 (2002) also pointed out that it is easy to manufacture the German patent DE l〇2 15 210.1 using the coating structure to propose a two-inversion type and that the light is extremely strong or completely transparent. OLED 、 However, the above coating structure has the disadvantage that the lateral 〇 LED structure required to constitute different color bismuth (Pixd) can be formed only on the display via the mask. However, this program is limited by the minimum size (<5〇m adverbine) $ that can be achieved. Throughout the manufacturing process, the masking process is a fairly time-consuming program. However, the inkjet (Ink_Jet) program is unusable because the small molecule cannot be dissolved. The US patent US 2〇_2〇〇73A1 relates to the application of the wire-forming hole transport layer to the vapor-mine interlocking layer and the electron transport layer. description of. The advantage of this configuration is that the polymer coating can be structured laterally and the full-axis display can be read and manufactured. However, the disadvantage of this configuration is that there is a problem with the carrier (electron from the cathode injection electron transport layer), which leads to the hybrid polymer small molecule OLED (hybriden p〇lymer side um〇lecule 〇 LED) The working voltage is increased. The purpose of the soil is to increase the flexibility of the construction of the illuminating element and to increase the efficiency of the carrier stream injection into the organic coating while maintaining the good structurability of the coating. The invention achieves the above object through the configuration of the φ coating structure, and the specific method is to configure at least one polymer coating and two molecular coatings, and is divided into the following rain conditions: if the top joint is _ 'that is The molecular coating that constitutes the coating of the most close to the contact of the ankle joint is coated with an organic or inorganic donor, which contains the main body of the financial institution f and the type of the application type. The material is 1246841, and the molecular weight of the dopant is greater than 200 g/m〇l; if the top contact is the anode, it also constitutes the most sin-like top contact coating. The layer is doped with an organic or inorganic acceptor which contains an organic host species and an acceptor species, and the molecular weight of the material is greater than 200 g/mol. The addition of the molecular coating can greatly increase the flexibility of the coating structure, and the presence of the polymer coating can achieve the purpose of improving the structurability without using a mask. The dopant should consist of an organic molecule, an inorganic molecule, or a metal-organic molecule having a molecular weight greater than 2 〇〇 g/md, and preferably greater than 400 g/md. 13⁄4 and it is important that the active doping (iv) molecular weight in the coating has such a large molecular weight (greater than g/md, and preferably greater than cc. For example, CS2C〇3 (cerium carbonate, molecular weight of about 324 g/ M〇1) The dopant as the n-type impurity-transporting electron transport layer does not meet the requirements of the present invention. The reason is that CSfO3 (cerium carbonate) is a relatively stable compound, so it cannot be $- or several The electrons go to another molecule (base material). However, when the temperature of the = money program exceeds 615t: (the splitting temperature), the knife can be split from the acid record. In theory, the planer can be used as a blend. The sundries will be an electronic smuggling, and 6 matrix material. However, the molecular weight of the planer is only about 132. Because the wire is used as a dopant, it is small by (10) molecules/atomic phase #, so after changing into the base layer, The secret, which will cause unfavorable shirting for the service life of the organic light-emitting element. Similarly, the Pna-doping__ is also the same as a hole transport layer with a strong acceptor (trans-p〇LED structure). Situation. In two molecular coatings formed by evaporation One is an undoped intermediate layer (component symbol 5 of the embodiment towel made in Machi), and the other is a 1268841 heterogeneous transport layer due to common luminescent polymers (eg Poly-phenylenvinylen, PPV). a kinetic energy barrier from the doped transport layer to the carrier stream of the polymer luminescent coating (if it is a conventional coating structure composed of a polymer hole transport layer disposed on a substrate, it means The potential for electron injection is too high, so an undoped intermediate layer must be added. The thickness of this intermediate layer is much smaller than that of the doped transport layer, and its LUMO (lowest unoccupied molecular orbital) energy level must be located. Between the doped transport layer and the lUM0 energy level of the luminescent polymer layer (if a hole transport layer is used, the ή〇μ〇 (highest occupied molecular orbital) energy level of this intermediate layer must be located at the doped transport The layer and the HOMO energy level of the luminescent polymer layer). This lion's way is to make the carrier stream easier to be injected into the luminescent polymer coating, and in addition to promote the luminescent polymer layer. Mixed with At the interface, there is a recombination process of (4) squirting, which is almost always happening under the surface energy of the pure shot. The configuration is related to the independent item. As for the manufacturing method, the method proposed by the present invention Set - a polymer coating and at least in the form of evaporation: set::: layer, and this molecular coating is - a hybrid molecule (4) The doping of the molecular coating is preferably in the true: 曰. Source to mix steam The plating method is carried out. “The separation of the control is controlled by a simple method. This structure can be used as a follow-up coating at the same time; using complicated structural steps or methods Eight/, the structure of the piece, without $

The setting of the knife coating is to avoid the limitation of the polymer coating due to the only two separate solvents of 1J 1264841, and to avoid the possibility of increasing the coating structure that is extremely different. Other specific embodiments of the manufacturing method of the present invention are contained in the subordinates of the independent items pertaining to the disc manufacturing method. Further, the present invention will be further described below in conjunction with a continuous embodiment. As shown in Fig. 1, a transparent brother bottom contact (2) as an anode is provided on the substrate (1). A polymer hole wheel, a layer (= first polymer coating, and a first polymer coating as a polymer luminescent coating = ) are sequentially disposed on the bottom contact ( 2 ). This coating structure consisting of the first polymer coating and the second polymer coating is made of PED〇T:pss (Baytr〇n-p, manufactured by H. C. Starck, Germany). The second polymer coating is based on the tomb, and the first molecular coating is used as the intermediate layer (5). The intermediate layer is made of a 10 nm thick Bphen (Batophenanthrolin) coating. Composition. Further, it is a second molecular coating as an electron transporting and injecting layer (6). This electron transporting and injecting layer (6) is composed of Bphen:Cs (molecular exchange concentration, and scoop 10 1 to 1 · 1). Composition. Finally, an aluminum top contact (7) at the top is used to form an organic light-emitting diode as shown in Fig.}. Since the molecular weight of the planing molecule is too small to be stably diffused in the lion layer, the age layer, the towel, and the age are not an appropriate dopant (responsible for supplying electrons). The present invention suggests that the molecular weight is greater than · curry 1 (preferably greater than 400 g/m 〇 D and the oxidation of the original potential is in the same range as the planer, the material acts as a dopant. _ standard oxidation of the original potential is 2.9.222 V, ionization The ionization energy of a 3.88 eV antimony dopant should be less than ~. For example, w〇m, am_Paddiewheel [W2 (hppW is the appropriate tumbler: 1264841

The ionization potential of the Wolfmm-Paddlewheel is approximately 3.75 eV. The structure of a negatively charged single hpp anion is as follows: The entanglement potential of the knives is 3·9 eV and the electrons of the Bphen coating are about 2_4 eV, which can be used to estimate the donor type of OLED transport materials. The ionization potential needs to be less than 4 leV. The conductivity of the S/cm to layer (Bphen:Cs in the above example) must be between IE·7. Between 3/Cm, and preferably in the middle layer of 1E-6 S/cm to 5E-5 S/cm scoop (BPhen in the above example), the conductivity must be between 5E 8 S/cm. That is to say, the undoped coating has a conductivity of 1264841 which is at least smaller than that of the lion's layer. The thickness of the lion's coating should be between 40 and 5 〇〇nm, and preferably the thickness of the undoped intermediate layer from 5 to 3 legs should be between 2 and 3 Between, and preferably between ^ 5 _ and 15 llm. Since the unintercalated coating is less conductive, its thickness must be much smaller than the thickness of the doped coating. The above requirements regarding coating thickness and conductivity also apply to the p-type doping of the hole transport layer in the following two embodiments. 2 will be implemented: the combination of the hole transport layer (3) and the luminescent coating (4) into a single-coat, which is replaced by a single-coat with two functions. Two coatings. In addition, you can also use the opaque material (for example: gold, Ming) to make the bottom contact (2), and the transparent top contact (7) as the cathode, for example, the IT0 layer manufactured by the money injection program: the contact (7). Since the coating (6) is doped, it is possible to charge from the ιτ〇 = two (6). If an organic dopant is used, the doping concentration should be between n and 1 · 2Q. If an inorganic dopant is used, the dopant should have a wavelength of between 1:1000 and 3:1. As can be seen from the μ, the organic light-emitting diode of the present invention is composed of a polymer coating layer and a molecular coating phase, and is hereinafter referred to as a coffee OLED. Fig. 2 shows the correction of the hair piece of the present invention. Figure 2 ==& structure is electrically opposite to the embodiment shown in Figure 。. In the age-old mode, the substrate (1) is provided with a cathode as a cathode: ? can be an opaque cathode (pure, paste, = 疋^_cathode_). A first polymer coating of the polymer electron transport layer (8) and a second polymer coating of the polymer light-emitting coating (4) are sequentially disposed on the bottom contact (7). Above the second polymer coating is a first molecular coating of the intermediate layer (9) which is deposited by evaporation, for example by a 10 nm thick TPD (tri-phenyldiamin, triphenyldiamine) coating. The intermediate layer (9) is formed on top of a second molecular coating as a hole transporting and >main entry layer (10), for example by doping F4-TCNQ with a molecular ratio of 50:1 ( Tetrafl face acyanoquin〇dimethane ^ tetracyanoquinone dimethane) m-MTDATA (tris (3 sylphyl ylphenylami yylphenylami) (3 methyl phenylphenylamino)-diphenylamine) hole transport and injection layer · G〇). Finally, a top contact (7) made of a transparent material (e.g., Tingyu) at the top is used as an anode to form an organic light-emitting diode as shown in Fig. 2. X. Other embodiments of the invention not specifically described herein include the alignment of the polymer coating and the arrangement of the molecules (4), that is, first an admixture is placed on the bottom contact (2) of the substrate (1). a heterogeneous molecular coating (1〇 or 6), and then a laterally structured polymer coating (4 and 8 A 3). Another possible way to apply is to apply a living polymer with an organic molecular coating. The luminescent coating is surrounded by φ. ' If the bottom contact (2) is used as the anode, the next coating sequence is sequentially molecularly doped hole injection and transport layer (1〇), intermediate layer (9) , a poly-person coating (4), an intermediate layer (5), a molecularly doped electron transport layer (1〇), and a cathode top impurity point (7). If it is a bottom contact (7) disposed on the substrate (1) The remaining order of the coating as the cathode 's should be laid down. 15 1264841 BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a first coating structure of an organic light-emitting diode of the present invention. a second coating structure of the organic light-emitting diode (as opposed to the coating structure of FIG. 1) (main Component symbol description] 2 bottom contact 4 polymer luminescent coating 1 substrate 3 polymer hole transport layer 5 intermediate layer (molecular coating) 6 doped electron transport and injection layer (molecular coating) 7 top contact 8 polymer electron transport layer 9 intermediate layer (molecular coating) 10 doped hole transport and injection layer (molecular layer) 16

Claims (1)

X. Patent application scope: 1. A light-emitting element with an organic coating consisting of a plurality of coatings between a bottom joint and a top joint on a substrate, the coating comprising a polymer Polymer coating, and a molecular coating consisting of small molecules coated in a vacuum, characterized by: at least one polymer coating (3, 4) and two molecular coatings ( 5,6), and is divided into the following two cases: - If the top contact (7) is the cathode, that is, a molecular coating that transports electrons that constitutes the coating closest to the top contact (7) and is coated with an organic or inorganic donor Doping, the n-type dopant comprises an organic main substance and a donor type dopant, and the molecular weight of the dopant is greater than 2 (8) g / mol; or 疋 · - if the top contact (7) is the anode, that is, the composition a coating of a p-type doped cavity molecule coated adjacent to the top contact (7) and doped with an organic or inorganic acceptor comprising an organic host species and an acceptor type dopant Heteroic, and dopant Molecular weight greater than 200 g/mol 〇 2. A luminescent element according to claim 1 of the patent application, characterized in that a polymer coating is formed which simultaneously forms a luminescent coating and a transport coating. 3. A light-emitting element according to claim 1 or 2, characterized in that two or more polymer coatings (3, 4) are provided. 4. A light-emitting element according to claim 1 of the patent scope, characterized in that only one 17 126484^ is provided There are noisy molecular coatings. 5. A light-emitting element according to claim 1, wherein the base material of the crucible is the same as the base material of the intermediate layer (5). Less miscellaneous coating (9) 6· '申# Patent range No. 1 of the light-emitting element, point (7) of the Bu | female /, Fu Zhiwei: at the bottom of the ",, () above the sigh one or several blends The impurity or undoped molecules, the coating of the sounding material are facing away from the bottom coating _-the upper side is provided with -= number == the coating is facing the bottom ^ as claimed in the scope of item 2 or item 2 Light-emitting element:: Set a polymer coating, at the same time on the polymer coating surface, the - edge of the joint (7) and the remaining part of the joint (7): molecular coating. It is characterized by: 2,7) 8· The light-emitting elements of claim 1 are all transparent. 9 The light-emitting element of the first item of the patent patent is characterized in that it is connected by a plurality of The layer is formed by an electrically-connected phase-light-emitting element. 1〇· As in the light-emitting element of claim 2, the 1st layer has a contact, and the connection layer can be controlled via this contact. Special · _ 9 or 1Q meal light-emitting elements, its characteristics 18 / 1264841 is · · The connection layer and / or the contact is transparent. A such as Shenxiang Township (four) crane Light 4,6,7, electron transport layer w〇Ifr.Paddlewheel[W2(hpp)4], where inch is the donor dopant in ____2η-ρ_μ1,2 斗咖铁n. Coating 13. The light-emitting element of claim i, wherein the conductivity is between IE-7 S/cm and IE-3 S/Cm. 14. The illuminating element of the scope of claim [...] The conductivity is between 1 Ε·6 S/em to 5 Ε·5 S/em 1. Bamboo '. 备 涂层 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 The conductivity of the hybrid coating is small - more than half. " For example, the thickness of the light-emitting element of the first application of the patent range is between 40 legs and the leg. The inch is the green coating doping coating. The doped R is a light-emitting element according to claim 1, which has a thickness of between 50 nm and 300 nm. A light-emitting element according to claim 1 is characterized in that the intermediate layer has a thickness of between 2 nm and 30 nm. 19 I2648^|^x ^ # I 19. A light-emitting element according to claim 1, wherein the undoped intermediate layer has a thickness of between 5 nm and 15 mil. 2 (λ) The light-emitting element of claim 1, wherein the thickness of the undoped coating is less than the thickness of the doped coating. 21. The light-emitting element of claim 1 is characterized in that: The ionization potential of the donor type dopant is less than 4,1 eV. 22. The light-emitting element according to claim 1, characterized in that if the organic dopant is used, the concentration of the dopant is 1:1000. Between 1:20; if an inorganic dopant is used, the concentration of the dopant is between 1:1000 and 3: 1. 23. Manufactured as in any of the claims 1-21 A method of illuminating a component by sequentially providing a bottom contact, a plurality of coatings, and a top contact on the substrate. The manufacturing method is characterized in that at least one coating is The coating is applied to the polymer coating, and at least one coating is a molecular coating that is deposited by evaporation, and the molecular coating is a doped molecular coating. The manufacturing method of item 23, characterized in that the doping of the molecular coating It is carried out in a vacuum by two separate controlled doping sources in a mixed evaporation manner. 20 126484^1 25, as in the patent application scope 23 or the 24th installation method j is characterized by: first in vacuum A dopant is produced from a lead material by evaporating an initial charge as a lead material to form a dopant during the evaporation process. 26. A manufacturing method according to claim 23 of the patent application, characterized in that To: if organic dopants are used, the dopant concentration is between 1:1000 and 1:20; if inorganic dopants are used, the dopant concentration is between 1:1000 and 3: 27. A method of manufacture according to claim 23, characterized in that the polymer coating is applied by means of ink jet printing (InkJet printing). A manufacturing method characterized in that: a luminescent coating (4) for producing a multi-color OLED is simultaneously produced by inkjet printing (Ink-Jet printing), and red, green, and blue bismuth (Pixel) are simultaneously produced. The manufacturing method of the 23rd item, The engraving is: the thickness of all the coatings is between 0.1 and 1 μηη. 30. The manufacturing method according to claim 23, wherein at least one polymer coating is applied from a solution by coating The mixed coating is either fabricated and doped by means of a coating material that is then applied to the polymer layer and then diffused into the polymer layer by 21 1264 咿 ' ? } "!, one, ..., ..." 31. The manufacturing method according to claim 23, characterized in that: Wolfula> Paddlewhed [W2(lipp) 4], wherein hpp is 1,3 '4,6,7, 8-Hexahydro (hexahydrogen) -2H-pyrimido - [1,2-a]_pyrimidin (mouth bite) as a donor-type dopant in the electron transport layer. twenty two